1. Field of the Invention
The present invention relates to an engine air intake device for supplying combustion air to an engine in a construction machine such as a hydraulic shovel.
2. Description of the Background Art
The background art is described by a hydraulic shovel (hereinafter, called as a conventional hydraulic shovel) disclosed in Japanese Unexamined Patent Publication No. 2005-248755.
The conventional hydraulic shovel has an engine air intake device for supplying combustion air to an engine. The engine air intake device is provided with two independent air cleaners, and an air expanding chamber (hereinafter, called as a merging chamber) for supplying air while merging the airs drawn out through the two air cleaners.
In the following, a layout of two air cleaners and a merging chamber, which is supposed to be designed for the conventional hydraulic shovel provided with two air cleaners and a merging chamber, is described by referring to a comparative example shown in FIGS. 7 and 8.
As shown in FIG. 7, a hydraulic shovel is provided with a crawler-type lower propelling body 1, an upper slewing body 2 slewably mounted on the lower propelling body 1, and a working attachment 3 attached to the upper slewing body 2.
The upper slewing body 2 is provided with an upper frame 2a, a cabin 4 disposed on the left side and on the front side of the upper frame 2a, a guard member 13 for covering the upper frame 2a from above, a first partition plate 7 for defining an engine room 5 between the upper frame 2a and the guard member 13, a second partition plate 12A for defining an air intake chamber 8A between the upper frame 2a and the guard member 13, an engine 6 and relevant devices disposed in the engine room 5, and an engine air intake device 9 disposed in the air intake chamber 8A.
An air intake port 14 (see FIG. 8) for drawing in external air is formed in a side portion of the guard member 13.
The air intake chamber 8A is formed on the front side of the engine room 5, with the first partition plate 7 being interposed between the air intake chamber 8A and the engine room 5.
The second partition plate 12A is adapted to separate the space where the air intake chamber 8A is disposed from the space defined on the front side of the second partition plate 12A.
The engine air intake device 9 supplies combustion air (external air) to the engine 6. Specifically, as shown in FIG. 8, the engine air intake device 9 includes two air cleaners 10A, 10B for filtering external air, and a merging chamber (also called as a merging box or a collecting box) 11 for supplying air while merging the airs filtered through the air cleaners 10A, 10B to the engine 6.
The first air cleaner 10A, the second air cleaner 10B respectively include air inlets 15, and air outlets 16, 16. The air inlets 15, 15 are opened toward the air intake port 14. The air outlets 16, 16 are connected to the merging chamber 11 through hoses 17, 17.
In FIG. 8, the reference numeral 18 denotes a partition wall for separating the air-intake-side space where the air inlets 15, 15 of the air cleaners 10A, 10B are disposed from the other space.
In the comparative example shown in FIGS. 7 and 8, the air intake port 14 is disposed with respect to the air cleaners 10A, 10B in the same direction as the aligned direction (left and right directions) of the air cleaners 10A, 10B, and the air cleaners 10A, 10B are disposed on a common horizontal plane in a state that the air inlets 15, 15 of the air cleaners 10A, 10B are respectively directed toward the air intake port 14. Because of the above arrangement, the conventional hydraulic shovel has the following drawbacks.
(i) The air cleaners 10A, 10B are required to be disposed to be offset relative to each other in the axial directions thereof (in the lengthwise directions of the rectangular-shaped air cleaner main bodies shown in FIG. 8) so that the air inlet 15 of the air cleaner 10B disposed on the rear side (upper side in FIG. 8) when viewed from the air intake port 14 may not be blocked by the forward-side air cleaner 10A. As a result, the planar space to be occupied by the air cleaners 10A, 10B when viewed from above is required to be increased in the axial directions thereof.
(ii) The partition wall 18 is formed between the air cleaners 10A, 10B. Accordingly, the interval between the air cleaners 10A, 10B is required to be increased, which results in an increase in the space to be occupied by the air cleaners 10A, 10B in a direction (left and right directions) orthogonal to the axial directions of the air cleaners 10A, 10B.
Because of the above two points, the space to be occupied by the air cleaners 10A, 10B is increased when the entirety of the engine air intake device 9 is viewed from above, and the air intake chamber 8A is required to be increased by the increased space for disposing the air cleaners 10A, 10B. As a result, the disposition of the devices to be installed in the air-intake-side space other than the air intake chamber 8A is restricted, and miniaturization of a construction machine cannot be sufficiently achieved.
Further, since the air cleaners 10A, 10B are disposed to be offset relative to each other, the distance from the air cleaner 10A to the merging chamber 11 is unduly increased, and the air cleaner 10A and the merging chamber 11 are required to be connected to each other by a hose 17 of a longer length, which makes the connecting operation cumbersome.